KR101301228B1 - Detachable edge ring for thermal processing support towers - Google Patents

Abstract

An edge ring 152 used for the wafer 30 batch heat treatment is supported on the vertical tower 140 in the furnace 160. The edge ring has a width substantially overlapping the wafer circumference and is evenly spaced between the wafers and detachably supported on the tower, reducing the thermal edge effect. The edge ring has internal and external recesses that are interlocked with the structure adjacent to the fingers of the tower legs 142, 144, 146 that support the wafer, or one or more steps formed on the transverse side of the edge ring are slid. May fall into the locking ledge associated with the support finger. Preferably the tower and the edge rings and the other portions 168, 180 of the furnace adjacent to the hot zone are made of silicon.

Description

Detachable edge ring for heat treated support towers {DETACHABLE EDGE RING FOR THERMAL PROCESSING SUPPORT TOWERS}

The present invention relates to provisional application number 60 / 697,895, filed on July 8, 2005, and provisional application number 60 / 721,926, filed on September 29, 2005.

The present invention generally relates to batch heat treatment of substrates, in particular silicon wafers. More specifically, the present invention relates to an auxiliary ring for use in a wafer support tower.

Batch heat treatment, in which the wafers are processed simultaneously in the furnace, continues to be widely used in the semiconductor art. Most recent batch heat treatments are based on vertical furnaces in which vertically arranged support towers hold a plurality of wafers in the horizontal direction. Conventionally, towers are made of quartz, especially for processing temperatures of about 1000 ° C. or silicon carbide, especially for higher processing temperatures, but silicon towers are commercially used in all temperature ranges.

One treatment using this heat treatment is hot temperature oxidation (HTO), where a very thin layer of oxygen is grown by chemical vapor deposition (CVD) using SiH ₄ and N ₂ O or NO as a precursor. . Typical CVD temperatures are around about 750 ° C. Thin oxygen has a thickness of around 2.5 nm or less and is used for tunneling barriers in flash memories, for example. Other treatments for growing thin films are possible, such as using O ₂ as an oxidant.

However, the thickness uniformity of the grown film is a problem. Thickness profile 12A is shown schematically in FIG. 1. Two peaks 14A, 16A within the thickness were observed near the wafer perimeter. Peaks 14A and 16A vary 16% and 33% on opposite sides, and because the tunnel current changes to an exponent of the thickness, a moderate change in thickness can significantly change the tunneling current, which changes the flash memory write performance. Can be given.

Although the specific starting point of the peak is not fully understood, possible causes are thermal edge effects, such as thermal shadowing, near tower legs or furnace walls and due to gas flow discontinuities around the wafer. It is considered to include. To solve this problem, a method of attaching the auxiliary ring at small intervals centered in the tower extending over the wafer edge has been attempted. To be optimized, the wafer is spaced between two neighboring edge rings facing its top and bottom surfaces. Edge rings have been shown to have a reducing effect even without removing peaks.

Typical designs include quartz towers and quartz edges, which melt as three or four tower legs. This design has certain problems. Although quartz is relatively expensive, melting at many locations is difficult. If one of the edge rings is an error in use, repair is almost impossible. Either the tower or the welded edge ring is discarded or the wafer near the edge ring that is faulty can no longer be used for wafer fabrication thereafter. Quartz is used as a general thermal support fixture, but the enhanced technology has questioned whether it is of adequate purity.

Therefore, a good design for the edge ring and its support tower is required.

The ring tower supports the wafer in a vertical stack with a generally annular edge ring sandwiched between the wafer, including fingers and other protrusions, and preferably extends over a radial band extending radially outward from the circumference of the wafer.

Preferably both the tower and the edge ring are made of silicon. The edge ring is more preferably formed of random oriented polycrystalline silicon (ROPSi), which can be grown in a Czochralski manner using polycrystalline seeds. The silicon seed may be composed of virgin polycrystalline silicon seeds grown by VCD or seed Czochralski-grown silicon grown from seeds traceable to virgin polycrystalline silicon.

Preferably, the rings are passively locked to the tower, for example gravity locked. The interlock can be made by a recess formed on the inner or outer circumference of the ring or by a step on the transverse side.

1 is a thickness profile of oxygen grown by high temperature oxidation treatment.

2 is a perspective view of one embodiment of the present invention having a tower and an edge ring.

3 is a side view of the tower and edge ring and wafer of FIG.

4 is an exploded view of one of the legs of the tower of FIGS. 1 and 2.

5 is a plan view of the edge ring of the present invention.

6 is a side view of the edge ring and wafer in a region away from the leg.

7 is a perspective view of another embodiment of an edge ring.

8 is a perspective view of a tower leg that the edge ring of FIG. 7 can use.

9 is a developed view of FIG. 8.

FIG. 10 is a developed view of a modification of the tower leg of FIG. 8.

11 is a top view of another embodiment of an edge ring configured for a four-leg tower.

12 is a perspective view taken from the front and rear of each of the arrangements between the edge ring of FIG. 11 and the side legs of the tower of FIG. 12.

FIG. 14 is a perspective view of a three-leg tower partially loaded into an edge ring that is a variation of the edge of FIG. 11.

FIG. 15 is a partial cross-sectional view of the edge ring and tower of FIG. 14, further illustrating a wafer.

16 is a side cross-sectional view of a heating furnace including a liner, an injector, and a tower.

One embodiment of the present invention is shown in perspective view in FIG. 2 and in side view in FIG. 3, comprising a support tower 10 comprising two side legs 12 and one rear leg 16, the lower end thereof. Is fixed to the lower base 18 and to a similar upper base, although not shown at its upper end. Legs 12, 14, and 16 are shown as exploded views in FIG. 4 and may similarly comprise and include fingers 22 generally projecting inwardly from leg stems 24 extending axially. In the corresponding axial position of the three legs 12, 14, 15, the finger 22 bears the edge ring 26 on the lower ring support surface 28 radially outward. Further, the fingers 22 support the wafer 30 on the upper wafer support surface 32 radially inward, the upper wafer support surface being generally flat and horizontal and defined by ridges 34 therein. do. Ridge 34 is closely located to the outer circular wafer 30 supported by the wafer support surface 32, thereby aligning the wafer 30 on the tower 10.

One edge ring 26 is shown as a top view in FIG. 5, which is generally a circular symmetric washer-shaped body about the center 40, which is the center of the tower 10 and the center of the wafer 30. It is intended to be common. However, the edge ring 26 is generally machined to include two similarly shaped two side recesses 42 and 44 and one rear recess 46, each of the two side legs 12 and 14 and Fasten the edge rings 26 on the rear legs 16. Thin segments within the recesses 42, 44, 46 support the edge rings 26 on the legs 12, 14, 16 of the tower 10. The outside of the segment 48 can be flattened, especially on its side, flat on the side parallel to the insertion direction, allowing for a wider outer diameter. The recesses 42, 44, 46 lie in a circumferentially extending position about the center 40 around the rear circumference of the ring 26 at a sufficient angle greater than 180 °, resulting in legs (eg, at similar angular intervals). 12, 14, 16 support edge ring 26 but side legs 12, 14 pass through side legs 12, 14 without interfering with insertion of edge ring 26 (and wafer 30). Small enough, for example, the center of the side recesses 42, 44 is located slightly ahead of the ring center 40.

The inner diameter of the edge ring 26 is approximately equal to or slightly larger than the diameter of the wafer, for example reaching 4-10 mm, for example greater than 6 mm. It is possible to extend the edge ring 26 somewhat into the wafer diameter smaller than 10 mm for a 200 or 300 mm wafer. Generally, deviations from the appropriate diameters result in a large pitch between the wafers 30 in the tower such that a substantial portion of the solid angle around the wafer edges can see the edge ring 26 or wafer 30 at the same temperature. Should not be exceeded. In other words, the wafer 30 edge should not see the furnace wall or liner, except through the gap between two neighboring edge rings 26, which represents the relatively small viewing angle of the liner. Similarly, the annular width of the edge ring 26 should be larger than the pitch between the wafers 30. The outer diameter of the edge ring 26 should be much larger than the wafer diameter so as to extend to an even outside temperature. The additional diameter may correspond to the position of the peaks 14A and 16A of FIG. 1 from around the wafer without the edge ring. As a result, most of the time, the wafer 30 can only see the other wafer 30 or the edge ring 26, all of which are about the same temperature. The largest temperature deviation is at the outer edge of the edge ring 26 rather than the outer edge of the wafer 30. Edge ring 26 must move uneven deposition peaks 14A, 16A out of wafer 30 region and onto edge ring 26. However, excessively wide edge rings affect the use and design of the oven. For example, the outer diameter should be 20 to 40 mm, for example 28 mm larger than the wafer. The thickness of the edge ring 26 should be large enough to provide sufficient strength to the ring-shaped structure but thin so as not to have much different thermal capacity than the wafer. In general, the thickness range is preferably in the range of about wafer thickness to about twice the wafer thickness. Modern designs use 1 to 1.5 mm thick.

The edge ring 26 is preferably machined from pure silicon, for example random oriented polycrystalline silicon (ROPSi), and melted chalk using, for example, a random oriented silicon seed. Czochralski-grown silicon, for example a virgin silicon seed or a polycrystalline silicon seed traceable to a CVD growth seed. Such metals and their growth and machining are disclosed in U.S. Patent Provisional Application No. 60 / 694,334, filed June 27, 2005, and U.S. Patent Application No. 11 / 328,438, filed January 9,2006. Reference is made. The fabrication process involves blending grinding after wire or saw cutting from a silicon ingot to create surface damage on the exposed surface and increase the bond of the film deposited thereon. Ceramic machining techniques are used to produce ring shapes from wafer-like blanks. The ring may be cleaned, for example, as a combination of acid or alkali etching after machining by the technique used to clean the silicon wafer, to remove impurities such as in particular heavy metals. After the manufacture of the edge ring 26 is completed, the same material deposited in the heater on all surfaces in the CVD process or the same material deposited in the deposition process to be used, i.e. silicon nitride in silicon nitride furnace and silicon dioxide in furnace Preference is given to pre-coating with CVD with silicon. This pre-coating layer will be firmly fixed in the cracks created as part of the cracks and surface damage and will bond well after the deposited layer of the same material.

Other types of silicon can be used, for example monocrystalline silicon. However, Czochralski-grown monocrystalline silicon is generally not useful for large diameters when needed for 300mm towers and can chip or crack. Cast silicon is available, which is typically random oriented and suitable for size, but its purity and often its strength is generally less than random directional CZ polysilicon. Silicon materials usable in accordance with aspects of the present invention should be understood that most of the aforementioned types of silicon are of higher purity but consist of at least 99 at% elemental silicon.

However, it should be noted that aspects of the edge ring of the present invention are not limited to silicon rings and towers, but may be made of other materials such as quartz, silicon carbide, or silicon-impregnated silicon carbide. Silicon-injected silicon carbide can be obtained by exposing the approximate stoichiometric silicon carbide to molten silicon or by blending a controlled amount of silicon and graphite powder and casting the mixture and heating it to obtain a selected ratio of silicon to carbon. Can be done.

Referring to FIG. 4, the legs 12, 14, 16 have a tendon 50 at their lower end and at the upper end, not shown, so that corresponding holes on the lower base 18 and the upper base not shown are shown. It is fixed inside. Fingers 22 extend radially inward from the leg stem 24 generally in a constant thickness and in a constant width section 52 in a horizontal direction, with a ring support surface 28 formed on top of the width section. The finger 22 then extends further radially inward, partially upwardly along the inclined section 54, which section is of constant thickness but is not necessary. The fingers 22 then extend further radially inward in the horizontal direction but collect the sidewall body 56 at a point within the wedge tip, which is connected on the radially outer surface by a ridge 34 on the wedge tip. The wafer support surface 32 is formed. The sidewalls 58 of the recesses 42, 44 in the ring 26 of FIG. 5 are similarly inclined to the tip sidewalls 56 but separated at somewhat larger intervals than the separated portions of the tip sidewalls 56. The edge ring 26 passes vertically by the side wall body 56.

As a result, the edge ring 26 can be manually or robotized into the tower 10 at a level on top of the ridge 34 of all three legs 12, 14, 16 in three corresponding sets of fingers 22. Can be inserted into the action. If the edge ring 26 has almost reached the stem 24 of the rear leg 16, the edge ring 26 is lowered and the recess sidewall body 58 passes through the tip sidewall body 56, so that the ring support segment 48 is positioned so as to rest on the ring support surface 28 of the legs 12, 14, 16. The inclined surface 54 of the finger 22 helps to center the edge ring 26 of the legs 12, 14, 16. If the edge ring 26 is placed on the edge ring support surface 28, it is left under gravity. However, if desired, the edge ring 26 may be removed in reverse order.

It is desirable that the vertical space between the wafer 30 and the edge ring 26 be controlled approximately. As shown in the side view of FIG. 6 taken along a radius that does not pass through the leg, the top surface 62 of the wafer 30 is separated by a gap A from the bottom surface 64 of the immediately above edge ring 26. And separated from the upper surface 66 of the immediately below edge ring 26 by a gap B. On the other hand, the intermediate face 38 of the wafer 30 is separated by a gap C from the bottom face 64 of the upper edge ring 26 and the gap D from the top face 66 of the lower edge ring 26. Separated by). The first design principle sets the space A = B. The second design principle sets the space to C = D. The former is for transient condition equality and the latter is for equilibrium uniformity. The design principles take into account the vertical division between the wafer support surface 32 and the edge support surface 28 of each finger 22, taking into account the vertical pitch of the finger 22 and the thickness of the edge ring 26 of the wafer 30. Decide by At the same thickness and alignment for the wafer and the edge ring, the average thermal loading between the wafer and the edge ring is generally considered to be constant. This figure shows that any wafer 30 sees the same area of another wafer 30 or another edge ring 26, both sets being substantially the same temperature and thus reducing the edge effect on the wafer 30. do. In addition, the bottom of the wedge-shaped finger tip is substantially on the bottom level of the edge ring 26, which is supported on the ring support surface 28, thus allowing wafer transfer after the edge ring 26 is located within the tower 10. FIG. It is desirable to provide a maximum tolerance for It should be noted that other design principles are possible which include various spacings in the axial direction.

After the edge ring 26 is loaded into the tower 10, the wafer 30 can be inserted and removed from the tower 10 without interference from the edge ring 26 that was already located. Edge ring 26 may be left in tower 10 for multiple wafer cycles.

If the edge ring 26 is faulty for some reason, it can be removed from the tower 10 and replaced with a new one without the need to make a new tower 10.

Another embodiment provides separate leg fingers for the wafer and the edge ring. As shown in perspective view in FIG. 7, the edge ring 70 includes two side recesses 72, 74 and one rear recess 76. All of the recesses 72, 74, 76 can be cut at right angles from the outer periphery of the ring 70, similarly shaped in the leg on the angular position corresponding to the recesses 42, 44, 46 of FIG. 5. Lose. The leg 80 shown fully in FIG. 8 and shown in exploded view in FIG. 9 can be used with either of the legs of the tower of FIGS. 2 and 3 to support and lock the ring 70. Leg 80 includes a wafer finger 82 and a ring finger 84 sandwiched therebetween, and generally extends horizontally radially inwardly from an axially extending stem portion 86.

Wafer fingers 82 each include a wafer support region 88, which is inclined to a horizontal or tip flat support tip region, if desired. The rear and radial outside of the wafer support region 88 are defined by the wafer ridge 90, which aligns the wafer on the wafer support region 82. The inclined sidewalls 82 on the outside of the wafer fingers 82 provide a wedge shaped tip. The ring fingers 84 each include a ring support region 94 that is typically flat and extends horizontally, on its rear side by ring ridges 98 located slightly rearward of the intended circumference of the edge ring 80. And on the front of the finger edge 96. The relative radius and axial positions of the wafer and ring support regions 88, 94 can be designed in the same manner as described above in the first embodiment.

Easily, finger edge 96 can be machined vertically at the same radial location on wafer ridge 90, which provides greater tolerance for wafer delivery. The finger step 100 formed at the rear of the ring ridge 98 has a width slightly smaller than its width and has other or similar general rectangular shapes of the ring recesses 72, 74, 76. The path 102 between the top of the finger step 100 and the bottom of the wafer finger 82 is thicker than the thickness of the edge ring 70, allowing the edge ring 70 to pass through it. Accordingly, the edge ring 70 can be inserted into the assembled tower by passing or sliding along the path 102 on at least its intended finger ridge 96 of the side leg. When the edge ring 70 reaches the intended position, ring recesses 72, 74, and 76 are positioned around each finger step 100, and the edge ring 70 passes through the side of the finger step 100. So that the edge ring 70 rests on the edge support region 94 and is mutually coupled to the finger step 100 by gravity. Once the edge rings 70 are all loaded, they may be left as subsequent wafer sets are loaded and unloaded from the tower. However, the edge ring 70 is removable from the leg for maintenance, replacement and other reasons.

A recess 104 behind the wafer support region 88 is typically required at least in the front leg, so that it is located at the center front of the supported wafer so that the total diameter of the wafer is inserted beyond the front leg to be downward on the wafer support surface. do. However, the depth of recess 104 may be reduced as shown in perspective view as leg 106 in FIG. 10. As a result, the fingers 82, 84 are less distinct.

As an embodiment of the leg 106 of FIG. 10, each wafer and ring fingers 82, 84 extend step 90 above the edge ring support region 94 at the rear of the wafer support region 88. Thereby combining in a single finger, joining with the finger ridge 96 and removing the recesses 104 behind the wafer support region 88. The resulting structure is below the ring support region 28 as opposed to the structure of FIG. 4 where the fingers 22 extend downward and a wafer support 32 is present on each finger. This leg 106 has the advantages of less machining and higher mechanical strength, but injects additional leg mass near the wafer edge. It is possible for the back leg behind the center of the wafer to be formed of a top and radial tier supporting the edge ring and a two stage finger at the bottom and radially inner end supporting the wafer.

Since the side recesses 72, 74 in FIG. 7 lock the edge ring 70 to the two front legs, no locking mechanism is required on the rear legs. That is, it is possible to remove the rear recess 76 in the edge ring 70 and extend to the leg stem 86 if possible behind the edge step 98 of the rear leg 80. Align the circular perimeter. Reduced machining is offset by separate designs and two types of legs.

Another edge ring 110 is shown in the top view of FIG. 11 and is configured for a tower having four legs 80. Two rear recesses and notches 112, 114 engage two rear legs 80, which are offset from the insertion axis 116 by the same opposite angle and face the center 40. The outer side 118 of the notches 112, 114 is cut close to the radius of the center 40, and the inner side 120 is cut parallel to the insertion axis 116 to facilitate loading on the leg 80. do. The inner flats 112, 124 are cut parallel to the insertion axis 116 but form a ring step 126 only partially backwards. Preferably, the ring step 126 lies forward in a direction perpendicular to the diameter passing through the center 40. The two side legs 80 at least partially preferably lie completely in front of the center 40 and direct the plane facing the insertion axis 116 vertically.

When the edge ring 110 is loaded, as shown in the front perspective view of FIG. 12, the inner flat portions 122, 124 are aligned with the wafer ridge 90 of each side leg 80, and the rear perspective view in FIG. 13. As shown, the ring step 126 falls down and is passively and gravity-locked to the side of the finger step 100 opposite the engagement of the edge ring 110 of the rear leg 80. In this position the edge ring 110 is stably supported by the rear legs distant from the rear of the center 40 and the front legs 80 which are slightly front rather than the full front of the center 40. As shown in FIG. 11, the outer flat portion 128 can be cut in the transverse side of the edge ring 110 parallel to the insertion axis 116 to load the edge ring 110 past the side legs 80. To reduce the transverse width of the tower and its legs. The part number and / or serial number 130 may be imprinted on the parallel surface of the edge ring 110.

The configuration of the side flat portions 122, 124 and the ring step 126 may be replaced by the side notches 72, 74 within the three-leg ring 70 of FIG. 7.

As described above with respect to the edge ring 70, the rear recesses 112, 114 of the edge ring 110 can be removed when the rear legs are configured separately to contact the circumference of the edge ring 110.

The edge ring 110 of FIG. 11 is designed for a tower having four legs. On the other hand, the tower 140, shown in partial perspective view in FIG. 14 and in partial cross section in FIG. 15, has only three legs, in detail, the upper end of which is fixed to the lower base 148 and the upper part is not shown. Two side legs 142 and 144 and one rear leg 146 fixed to the base. As shown, the side legs 142, 144 are located completely forward at the center 40 of the tower 140, wafer 30 edge ring 152. Notches 150 are formed in both the rear of rear leg 146 and the rear of base 148 to accommodate thermal coupling to measure temperature near the wafer. Fingers are formed in legs 142, 144, and 146 to support edge ring 152 and wafer 30 (not shown in FIG. 13). The fingers are different between the side legs 142 and 144 and the rear legs 146 to allow the side legs 142 and 144 to pass through the side steps of the edge ring 152. The inner circumference of the edge ring 152 is spaced slightly around the outer circumference of the wafer 30 except for the inner flat portion 154 that is almost circular about the center 40 and slightly hangs the wafer 30. The outer circumference of the edge ring 152 is substantially circular about its center but passively internally locks the edge ring 152 to the legs 142, 144, and 146, including two side steps and one rear notch.

It is expected that after an extended operation of the deposition process the film thickness will reach a thickness sufficient for particle flaking on the tower 10 and the edge rings 26, 70, 110, 152, which can be problematic. Even in this case, it may be possible for the deposited film to attach the edge ring to the tower 10 by mutual bridges. There is a general procedure for cleaning films from silicone. Thus, both the silicon tower 10 and the attached silicon edge ring can be placed in an etching bath that removes the deposited layer without removing the underlying silicon. For example, HF removes silicon oxide and silicon nitride from silicon. Some of the silicon has greater selectivity in cleaning compared to some of the quartz. In the case of a broken ring it is possible that a similar tower and ring etch is performed to remove the broken edge ring with the debris bonded to the tower before the debris is removed.

It should be noted that the shape of the edge ring is not limited to the above.

While silicon edge rings offer greater advantages, the removable feature of the present invention is also useful when the tower or edge ring is made of other materials such as quartz, silicon carbide, or silicon implanted silicon carbide. The simple structure of the rings and towers and the ease of regrinding can provide all materials with important manufacturing economics.

The present invention is not limited to the HTO process described above and may be useful for other processes, possibly other process gases, silicon, silicon-on-insulators or other wafers such as glassy or ceramic substrates and other process temperatures. The present invention is most useful for high temperature treatments but can be applied to low temperature treatments such as chemical vapor deposition.

If the edge ring is made of silicon, all silicon-hot regions may be useful in furnaces for large scale commercial production. The vertically arranged furnace 160 shown in cross section in FIG. 16 includes a thermally insulated heater canister 162, which is a resistive heating coil powered by a power source (not shown). 164). A bell jar 166, typically made of quartz, includes a roof and fits within the heating coil 164. For example, a liner 168 that is open at the end is fitted to the bell-shaped ego 166. The support tower 170 corresponding to the tower described above has three or four legs 172 fixed to the upper and lower bases 174 and 176 or supporting edge rings and wafers, not shown. The support tower 170 rests on the pedestal 178. During processing, pedestal 178 and support tower 170 are generally surrounded by liner 168. One or more gas injectors 180 having outlet ports of different heights are positioned between the liner 168 and the tower 170 and have outlets for injecting processing gas at different heights as the liner 168. A vacuum pump, not shown, removes process gas through the bottom of the bell ego 166. The heater canister 162, bell ego 166 and liner 168 may rise vertically so that the wafer is delivered to the tower 170 and from the tower, but in certain configurations these members remain fixed and the riser is heated. The pedestal 178 and loaded tower 170 are raised and lowered into and out of the bottom of the furnace 160.

The bell ego 168 is closed at its upper end and causes the furnace 160 to have a generally high temperature generally at the top of the center of the furnace. This is referred to as the hot zone where the temperature is controlled in the optimized heat treatment. However, the open bottom end of the bell-shaped ego 168 and the mechanical support of the pedestal 178 allow the bottom of the furnace to have a low temperature, which is as low as a heat treatment without chemical vapor deposition. The hot zone may include some of the lower slots of tower 170.

It is preferred that the tower, liner and injector as well as the edge ring consist of silicon so that all the materials in the hot zone are made of the same silicon material as the silicon wafer to be treated with very even purity. In addition, silicon baffle wafers can be used, which is described in the provisional application No. 60 / 694,334 described above. All silicon hot zones have very low particle levels and impurity levels in silicon wafer processing. Boyle et al. Describe the manufacture of silicon towers in US Pat. No. 6,450,346, and the silicone liners in US patent application Ser. No. 10 / 642,013, filed Aug. 15, 2003 and now published in US Patent Application Publication 2004/0129203 A1. This is referred to in this application. Zehavi et al. Describe the manufacture of a silicone injector in U.S. Application No. 11 / 177,808, filed July 8, 2005, which is incorporated herein by reference. Boyle et al. Describe silicon powder and spin-on glass for assembling silicon structures in US Patent Application Publication 2004/0213955. All these silicon parts are available from Integrated Materials, Inc., Sunnyvale, California.

The present invention provides a structure with improved thermal function and reduced contamination and particles, which is economical to manufacture and easy to maintain.

Claims (26)

As a tower assembly, A vertical support tower extending between two bases and each of the two bases and including a plurality of legs fixed to each of the two bases; A plurality of fingers extending radially inwardly from each of the plurality of legs to detachably directly support a plurality of horizontal wafers arranged in parallel and detachably directly support a plurality of edge rings sandwiched between the plurality of horizontal wafers; field; Wherein the edge rings extend radially outward beyond the diameter of the wafers, Each of the plurality of fingers, A radially inner wafer support surface located at the wafer support surface level; A radially outer ring support surface positioned at a ring support surface level below the wafer support surface level; A ridge located outside the diameter of a wafer supported on a wafer support surface for aligning wafers on the tower, the ridge extending above the wafer support surface level; And Including an inclined section extending between the ridge and the radially outer ring support surface Tower assembly. The method of claim 1, The vertical support tower is made of silicon, Tower assembly. The method of claim 1, The tower assembly further comprises the plurality of edge rings, Tower assembly. The method of claim 3, wherein The vertical support tower and the plurality of edge rings are made of silicon, Tower assembly. 5. The method of claim 4, Wherein each of the plurality of edge rings comprises random oriented polycrystalline silicon, Tower assembly. 5. The method of claim 4, Wherein each of the plurality of edge rings comprises Czochralski-grown polycrystalline silicon Tower assembly. The method according to claim 1 or 3, The vertical support tower comprises a material selected from the group consisting of quartz, silicon carbide, and silicon-impregnated silicon carbide, Tower assembly. delete delete The method of claim 3, wherein Each of the plurality of edge rings is annular, Each of the plurality of edge rings includes a plurality of radially inner recesses for engaging the fingers, each of the plurality of radially inner recesses forming a segment portion that can be supported by the ring support surface, each segment And located radially outward of each of the plurality of radially inner recesses, Tower assembly. delete The method of claim 3, wherein Each of the plurality of edge rings is annular, Each of the plurality of edge rings includes a plurality of radially inner recesses for engaging the fingers, each of the plurality of radially inner recesses forming a segment portion that can be supported by the ring support surface, wherein the segment portion Located radially outward of each of the plurality of radially inner recesses, Tower assembly. The method of claim 3, wherein Each of the plurality of edge rings includes a back recess for engaging one of the rear sides of the plurality of legs; Tower assembly. Tower and edge ring assembly, A vertical support tower for supporting a plurality of wafers and a plurality of edge rings, wherein each of the plurality of wafers and each of the plurality of edge rings are oriented horizontally and the plurality of wafers are defined by the plurality of edge rings. Inserted vertically, The vertical support tower is: Lower base; Upper base; A plurality of legs; And A plurality of annular edge rings; Each of the plurality of legs is fixed to the lower base at a lower end and to the upper base at an upper end, two or more of the plurality of legs include a plurality of fingers protruding inwardly from the leg, Each of the plurality of fingers is: A radially inner wafer support surface located at the wafer support surface level; A radially outer support surface positioned at a ring support surface level below the wafer support surface level; A ridge located outside the diameter of the wafer supported on the wafer support surface for aligning the wafer on the vertical support tower, the ridge extending above the wafer support surface level; And An inclined section extending between said ridge and said radial outer ring support surface; / RTI > A plurality of annular edge rings are included to be detachable within the vertical support tower, each of the plurality of annular edge rings having a central gap across one or more of the plurality of wafers, each of the plurality of annular edge rings Extends radially outward beyond a periphery of the plurality of wafers; Each of the plurality of annular edge rings forming a plurality of radially inner recesses to engage each of the plurality of fingers; And Each of the plurality of radially inner recesses defines a segment portion supportable by the ring support surface, the segment portion being located radially outward of each of the plurality of radially inner recesses, Tower and edge ring assembly. 15. The method of claim 14, Each of the plurality of edge rings has an inner diameter in a range of ± 10 mm of the diameter of the plurality of wafers, Tower and edge ring assemblies. 16. The method according to claim 14 or 15, Each of the plurality of edge rings and the vertical support tower is made of silicon, Tower and edge ring assembly. As an edge ring, Removably supported by a wafer support tower having an insertion axis and a plurality of fingers protruding inwardly from a leg extending in the axial direction, each of the plurality of fingers having a radial outer ring support surface and a radial inner wafer support surface. Wherein the tower separates and supports process wafers and one or more edge rings, wherein the edge ring comprises: An annular member having an outer diameter greater than the diameter of the process wafers; And A locking mechanism that is removable manually and by gravity; / RTI > The locking mechanism is: (Iii) a plurality of recesses formed in the inner periphery of the annular member corresponding to the plurality of fingers, wherein each of the plurality of recesses is a radially outer segment of the recess for supporting an edge ring on a ring support surface; And the radially outer ring support surface is lower than the radially inner wafer support surface, each of the plurality of recesses removably locking the edge ring by a leg extending in a corresponding axial direction. A plurality of recesses, and, (Ii) two inner flats and two outer flats extending parallel to the insertion axis on the outer periphery of the annular member, each inner flat extending laterally between the outer flats; Two inner flats connected by outer steps to the outer flats, the annular members being placed in a wafer support tower along the insertion axis and configured to be lowered to lock each step manually by each of the legs by gravity; And two outer flats, Composed of one of Edge ring. 18. The method of claim 17, Wherein the cyclic member comprises at least 99 at% of silicone, Edge ring. 18. The method of claim 17, Wherein the cyclic member comprises a material selected from the group consisting of quartz, silicon carbide, and silicon-infused silicon carbide, Edge ring. A support tower and edge ring assembly for supporting a plurality of circular substrates, the support tower and a plurality of edge rings, comprising: The support tower is: Two bases; A plurality of legs fixed to the two bases and arranged about a central axis; Including Two or more legs of the plurality of legs are each; Stem portion; A plurality of wafer fingers having a bottom and a first support surface;  A wafer ridge extending vertically from the rear side of the first support surface; A plurality of ring fingers having a bottom and a second support surface; A ring ridge extending vertically from the rear side of each of the plurality of second support surfaces; And A finger step extending horizontally between the ring ridge and the stem portion; Wherein the plurality of wafer fingers are axially arranged along a stem portion for supporting the substrates, the first support surface extending from a first axis to a second radius greater than the first radius from a central axis; A plurality of wafer fingers is fitted to the plurality of ring fingers in an axial direction to support an edge ring, and the second support surface is a fourth radius greater than the third radius from a third radius greater than the first radius Extending to the finger step, which forms a passageway between the finger step and the vertically adjacent wafer fingers, The plurality of edge rings, An annular member having an outer diameter greater than the diameter of the plurality of circular substrates; Two inner side flats and two outer side flats extending parallel to the insertion axis and located on an outer periphery of the annular member; Including, Each inner flat portion is connected with the outer flat portion by a ring step extending laterally between the inner flat portion and the outer flat portion, and the annular member is inserted through the passage in the wafer support tower along the insertion axis. Configured to be lowered by each ring ridge to manually lock each ring step by gravity, Support tower and edge ring assembly. 21. The method of claim 20, The size of the third radius is greater than the size of the second radius, Support tower and edge ring assembly. 22. The method according to claim 20 or 21, Each wafer ridge extending between a first support surface of one of the wafer fingers and a bottom vertically adjacent one of the plurality of fingers, Support tower and edge ring assembly. delete delete 22. The method according to claim 20 or 21, Each of the plurality of legs comprises a material of any one of silicon, quartz, silicon carbide, and silicon-infused silicon carbide, Support tower and edge ring assembly. As a furnace assembly, A silicon liner sized to fit the furnace; A silicon tower sized to fit within the liner to support a plurality of wafers and a plurality of edge rings; Including, The plurality of wafers and the plurality of edge rings are vertically spaced apart and fitted horizontally parallel to each other, The silicon tower, Lower base; Upper base; A plurality of legs each of which is fixed to the lower base at a lower end thereof and each of which is fixed to the upper base at an upper end thereof; One or more silicon gas injectors sized to fit between the tower and the liner; And A plurality of silicon edge rings removably contained within the tower and having a central opening formed over one or more of the plurality of wafers and over an edge ring extending radially outward beyond the periphery of the wafers; / RTI > Two or more of the plurality of legs include a plurality of fingers protruding inwardly from the leg, Each of the plurality of fingers, A radially inner wafer support surface located at the wafer support surface level; A radially outer ring support surface positioned at a ring support surface below the wafer support surface level; A ridge extending above the wafer support surface level as a ridge located outside the diameter of the wafer supported on the wafer support surface to align the wafer on the tower; And an inclined section extending between said ridge and said radially outer ring support surface, Each of the plurality of edge rings comprises an annular member having a plurality of radially inner recesses for engaging the fingers and each of the plurality of radially inner recesses is located radially outside of each of the plurality of radially inner recesses To form a segment portion supportable by the ring support surface, Furnace assembly.

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